Player piano



C, GULBRANSEN PLAYER PIANO Filed Oct. 16, 1924 2 Sheets-Sheet C977. rfefz tor 6722156 can @u Zrcme'z Oct 2, 1928.

C. GULBRANSEN K PLAYER PIANQ* med o =t.1s., 1924 2 sums-sneer yay *Zaun/V All.

the purposes of the present invention, may be ing strips removed,

Patented Oct. 2, 1928.7

UNITED STATES PATENT OFFICE.

oHnIsTIAN auLBRaNsnn, on. cnicas-c, Immers; AssIGnon, To GULBRANSEN com- PANY, oli' CHICAGO, ILLINOIS, A ooRIroRA'IIoN` 0F ILLINOIS.

PLAYER PIANO.

Application led October 16, 1924. Serial No. 743,866.

My invention relates to player pianos and more specifically to an improvement in the pneumaticl stack of a piano.

Among the lobjects of the invention may be enumeratedthe minimizing ofl the volumetric capacityof the stack, 'and the simplificationot' the mechanical details of construction of the channel board Vand thc pneumatics mounted thereon. l

In the*accompanyingdrawings, Fig. 1 is an end elevation partly intran'sverse section o a stack according to the invention;

Fig. 2 is a plan and Fig. 3 a central section ofthe valve block4 and valve for one of the unit pneumatics;

Fig. 4 is a face view of the grooved side of the channel board with part of theV cover- Fig. 5 is a section 4; and

Fig. Fig. 4. n

In the embodiment of the invention selected for illustration, the face of the channel board 10, to which the unit pneumatics are to be attached, is left smooth.' kIn the opposite face `there isformed a small groove 12 hereinafter referred to as the bleed header and three somewhat larger grooves 14, 16 and 18, each forming a header for one o'fi the tiers ofpneuinatics. As shownclearly in F igs and 6, these grooves extend into the on the line 5-5 ot' 6 kis a'seotion on the line 6 6 yof channel board to'somewhat less than half its thickness, leaving a solid portion adjaindependent passageways. VAt one end of the channel `board branched tubes'20 Vcommunicate through holes 22 with headers 14, 16 and 18, and the branched tubes units into a single vsuction supply tube 24 which, for

considered the source of` suction for operating the stack.

The dimensions of headers 14, 16Y and 18v are Ithe minimum necessary to provide adequate communication between the source of" suction and allthe pneumatic-s on the stack. lo facilitate making the headers of minimum size, I provide vert-ical cross oo nnecting'passages 26, three at the end ot the channel board and others at uniform intervals throughout the length thereof.' In case a large number of pneumatics all in the samek tier should simultaneously be called into actionfby the notesheet, the headers for the other tiers will furnish parallel paths of communication through passages 26. This makes it possible to use somewhat smaller headersthan would otherwise be practicable. Cross passages 26 also form the sole source of supply for the bleed header l2, with which they communicate, as clearly shown in F 4.

Supply passa-ges for the Yindividual pneumatics areV formed at 28. By locating these so that they communicate with the lower edges of the headers, the pneumatics may be so positioned that the fastening screws 30 threaded into holding pins 32 to clamp each unit pneumatic in place; on the Channel board, may pass through an entirely solid portion of the board. This makes screws 30 a simple, mechanical fastening, entirely independent vof the pneumatic passageways,

screws 30 lie just below the lower edges oi' i the sealing strips 35 for the headers.

The control passages for the individual 'pneumatics are formed near the smooth face oi' the channel board, being drilled in from the upper edge parallel tocross passages 26. Thus, in Fig. 4, the short passage 36 runs down to the irst pneumatic, the next passage 38 runs down to the first pneumatic in the second tier, and the long passage 40 runs down to the first pneumatic inthe bot-tom tier. By staggering the pneumatics as clearly shown in Fig. 4, it is easy to mis-match the holes. Thus passage 36 goes down betweeny the supply passage and one of the screw holes for its pneumatic, passageway 38 passes the first tier between the same supply hole and the other screw hole, and passage 40 passes the uppertier between the screw holes for adjacentv pneumatics, and passes the second tier between the supply passage and screw hole for n the pneumatic operated through passage 38. 7

From header 12a cross passage 42 runs to eachl control passage, said cross passages being substantially closed by metal'cups 44 having accurately calibrated bleed orilices.

I prefer to connect the vertical control passages from theitracker lbar to the smooth face of thechannel board. yFor this purpose ydiagonal* holes 46 are drilled yin this face to connect with each vertical control channel, and metal nipples 48 'may -he inserted for suitable connectioniivith, the Vflexible tubes running to the tracker bar. p

VEach pneumatic coni-prises a fixed leaf anda hinged leaf 52 connected theretoV by a Y' suitable fabric hinge 54. rIhese Aleaves may be duplicates originally and differ in the finished pneumatic only by the formation of a hole 56 in the upper leaf'andthe aliix- .ing of av silencing and check pad 58 tothe upper surface ofthe lower leaf and an eX- tensiony 60 to the .lower surface to underlie the abstract 62.` e Y To make itpossible to employ leaves of the simple shape shown, it is necessary, to

^ form hoththe valve chamber64 and the-'diaphragm chamber .56 in theV block 68. The block is accordingly provided -with a large bore 70 of the proper diameter to receivethe diaphragm 72, continued by a smaller bore 74 housingthe`V disc ,76 and easing pad 78 which carry the valve stem 8O.V Control passage82 registers withthe vertical control passage in the channel board, and opens lie- Vlow the diaphragm l72, while the inclined supply passage '84'opeiis above the diaphi'agin and registers with the supply passage 28. Above tlieboreSG, housing valve I stem 80, thev blockis enlarged to receive the lower valve seat 88, and again .at to form the valve chamber64, housing valve 92, movable between the `lower seat 88 and the upper seat 93 attached to the top of the block (38. Vertical bores 94 and horizontal bores 96 in the corners of the block are formed to receive `holdiner .pins 32 and fastening screws 30, respectively. From valve chamber 64 twin passages 100 lead to pocket 102 which registers with hole 56 in the iled leaf.

It will be apparent that in the construction disclosedno machining of leaves 52 and 50, except the formation ofthe single hole 56 in the upper leaf is necessary, all the more intricate shapes being lformed in block 68.

This materially simplifies thev process of manufacture, and it is also'possible, if desired, to use a different grade of wood for theleaves, as it is not necessary to have marterialin them that will standV machining into the intricate shapes formed in the block.-

lt should also `be noticed that the block is the only element ofthe pneumatic engaging the .face of the cliannel'board. vBoth the supply and the cont-rolfpassages' are formed in the y ceiving thehinge strip 5 4. p y A singlesealing-.strip 104 .will'forma Vcom- Y block, and the inner end of the upper leaf 50 has noj-function to perform except repleteseal foifall the vertical passages in the channel board,both cross passages and control passages, each of the ,pneumatic 4headers'can be sealed by anindividual seal-A f ing. Siep 35 and the bieai header 12 is `Sensi with crownstripy 10.6." Certain-portions ofV header l2 may be plugged with plugs 1l and the crown strip cut away to form points 1,cse,153

of attachment Vforhingesi vThe-formation of the diagonal passages 46 not only permits this simple seal to be used, but makes it possible to inclinetubes 48,V as clearly indicatedV in Fig: 7 ,at the'inost advantageous angle for connection to the flexible tube running to the tractor bar.

1Without further elaboration, the foregoing Vwill so fully explain the gist of my invention, that others may, by applying cur-l rent knowledge, readily adapt theV samel for use under various conditions of service, without eliminating certain features which .mayl properly be said to constitute theressential items of novelty involved, which` items are` intended to be delined andjsecured to ,ine

by the following claims.

I claim: l Y

l. In a pneumatic stack, infcombination, a channel board having three large grooves and one small. groove` formed in oneface thereof, a direct connection 'to each large groove for delivering suction thereto, three tiersV of unitV pneumatics secured against the opposite face of said board andepositioned to register with said large. grooves, fasten-gy y ing screwsfor each unit pneumatic eXtend- Y ing-through solidV portions o fvrsaid board to the opposite side for convenient access, transverse equalizing passages eXten'dingin from one edge of said board to interconnect all four grooves, transverse individual control passages Vextending in from the same edge pastsaid grooves near the opposite'faceV of VVface thereof, rtiei'sof unit pneumatics secured against the opposite face of said board and.'

positioned to Yregister witheach' groove, Y

transverse individual control passages er;- tending in from one edge of said board past said grooves near the opposite face of said board to register with said unit pneumatics, e

an ladditional groove, and bleed` passagesrconnecting eacli conti-ol passage with said last mentioned groove. y v 'Y 3. In a pneuinaticstackyin combination', a channel board having large grooves and one small groove'formerd in one facev thereof, a direct connection to eacli'large groove for delivering suction thereto, tiers ofiv unit pncumatics positioned to register with said large grooves, fastening screws for eachV unit" pneumatic extending through solid portions of said'board to theopposite side'forcons venient access-transverse equalizing passages isov extending in from one edge of said board to inter-connect all four grooves, transverse mdividual control passages extending 1n the board to said control passages, sealing strips covering all said grooves, and a single sealing strip covering the ends of said equalizing and individual control passages.

4. In a pneumatic stack, in combination, an integral channel board having rows of channels extending longitudinally thereinV4 and open at one face of said board, closure strips covering the open sides of said channels, and tiers of unit pneumatics secured against the opposite face of said board and in alignment with said channels and connected with said channels through passageways extending transversely through said board. Y

5. In a pneumatic stack, a channel board having a plurality of longitudinally disposed channels extending inwardly from one face of the board, closure strips secured to said face of the board and closing said channels, and pneumatic units secured on the opposite face of the' board and arranged in rows disposed in alignment with the respective channels, said board having air passageways extending from said opposite face thereof and establishing direct communication between the respective pneumatic units and the channels of t-he board.

6. In a. pneumatic stack, a one piece channel board having a plurality of' longitudinally disposed channels extending inwardly from one face of the board, closure strips secured to said face of the board and closing said channels, pneumatic units secured on the opposite face of the board and arranged in rows disposed in alignment with the respective channels, the board having an additional channel extending inwardly from the first mentioned face thereof, a closure strip over the outer side of said additionalchannel, the board having passages extending from one edge thereof and disposed between the channels and said other face of the board, said passages communicating with the pneumatic units and the board having bleed openings establishing communication between the passages and said additional channel, the board being further provided with passages extending from said other face thereof and establishing direct communication between the respective units and the channels, and means for connecting all of the channels to a suction source.

7. In a pneumatic stack, a channel board having a plurality of longitudinally disposed channels extending inwardly from one face of the board, closure strips secured to said face of the board and closing the outer sides of the channels, pneumatic units at the opposite face of the board and arranged in rowsdisposed in alignment with the respective channels, said board having air passageways extending from said opposite face thereof and establishing communication between the respective units and the channels of the board at the edge portions thereof, and securing members passing through the board from the first mentioned face thereof and between the channels, said members securing the pneumatic units to the opposite face of the board.

8. In a pneumatic stack, a one piece channel board having a plurality ofY channels extending inwardly from one face of the board and disposed longitudinally thereof, strips closing the out-er sides of the channels, and pneumatic units at the opposite face of the board and arranged in rows disposed in alignment with the respective channels, each unit including a valve block secured to the board and a pneumatic secured to the block, the block having an air passage and the board having an air passage extending from said opposite face thereof and establishing direct communication between the channel and the passage of the block.

VIn witness whereof I hereunto subscribe my name this 10thy day of October, 1924.

CHRISTIAN GULBRANSEN. 

